1. Field of the Invention
The present invention relates to mowers and, more particularly, to a mower having a cutting blade which retracts in response to an obstruction.
2. Brief Description of the Prior Art
U.S. Pat. No. 3,045,413 to Sheffer generally discloses a cutting blade and guard attached to a springed, laterally extending post. The cutting blade, guard, and post are supported by a hydraulic lever arrangement. The cutting blade is rotated by a motor, belt, and pulley.
U.S. Pat. No. 4,901,508 to Whatley generally discloses a fence row mower with a plurality of rotary blade units driven by a series of pulleys. Pressure cylinders are used to maneuver the plurality of rotary blade units.
In general, the known prior art must be supported or maneuvered by complex means, such as by pressurized fluid systems. This is expensive and adds to overall maintenance costs. Moreover, the prior art teaches using complicated blade drive units to rotate a cutting blade. Therefore, a need exists for a mower with a simplified cutting blade driver and a cutting blade that extends and retracts quickly from a utility vehicle without the need for complex fluid pressure systems.
In order to help satisfy the needs not currently met by the prior art, one embodiment of the present invention generally includes a mower adapted to follow terrain and retract in response to an immovable obstacle. The mower generally includes a utility vehicle, an attachment frame configured to be pivotally attached to one side of the utility vehicle, a secondary frame pivotally connected to the attachment frame, and a housing positioned adjacent to the secondary frame. The housing is preferably laterally movable with respect to the secondary frame via biasing means. In one method of operation, the housing retracts in a direction toward the secondary frame when contact occurs between the housing and the immovable obstacle and automatically returns to a pre-contact position when contact between the housing and the immovable obstacle is eliminated.
In sum, the present invention seeks to improve the mower art by providing a mower with an automatically biased cutting blade assembly. No hydraulic lifts or actuators are required to move the cutting blade assembly or to pivot the cutting blade assembly in response to uneven terrain. The cutting blade is directly attached to a vertical shaft, which in turn, is directly connected to a motor. When an immovable object, such as a fence post, is encountered, the automatic biasing action of the cutting blade housing helps to quickly and automatically return the cutting blade to a pre-contact position and significantly eliminates spots of uncut vegetation growing between adjacent fence posts.
These and other advantages of the present invention will be clarified in the description of the preferred embodiment taken together with the attached drawings in which like reference numerals represent like elements throughout.